towards a simpler entry point
finish removing six
remove PY2 tests
make importing play nice

(with both nosetests and CL)
small tightening
remove support for generators
Don't support DELETE_FOO

We're leaving in DELETE_NAME for now so that the following form still works:

`except Exception as e:`

which emits a DELETE_NAME for `e` at the end of the except block.
Remove support for closures

This also kills decorators.
more generator cruft
Remove support for context managers
remove DUP_TOP_TWO
remove inplace operators
Drop support for eight more opcodes
inline PEEK
remove support for exception causes
more generator control
inline push_frame
Simplify entry point

Drop support for CL args, be slightly sloppier
tweaks
remove graceful error on bad method